<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>01_BOM操作</title>
</head>
<body>
<button onClick="alert('请先登录！')">弹出警告框</button>
<button onClick="confirm('确定删除吗？')">弹出确认框</button>
<script>
    //window是浏览器内置的全局对象，无需创建或导包，直接使用其属性与方法
    //
    console.log(parseInt(6.6));
    console.log(parseInt(6.1));
    console.log(parseInt(6));
    console.log(parseInt('6.99'));
    console.log(parseInt('hhh'));

    //parseFloat():将参数转换成小数，如果得不到数字
    console.log(parseFloat(6.6));
    console.log(parseFloat(6.1));
    console.log(parseFloat(6));
    console.log(parseFloat('6.99'));
    console.log(parseFloat('hhh'));

    //
    console.log(isNaN('hhh'));
    console.log(isNaN(6.6));
    console.log(isNaN(6));
    console.log(isNaN('6'));



</script>
</body>
</html>